Richard Zimmerman, age 7, of Rochester, New York, or his question;

Are teeth bones?

Teeth wore invented by an ancestor of the shark, millions and millions of years ago. To be on the safe side, this fellow grew teeth all over his body as well as in his mouth. These first teeth were small prongs made of soft pulp encased in shells of tough enamel. The modern shark is still a toothy fellow. Not only has he a mouthful of teeth, but he still wears small toothlets scattered through his skin.

Our teeth are also encased in shells of tough enamel. Under the shell of enamel is a hard stuff called dentine. Dentine is very much like ivory. In the center of each tooth is a soft pulp full of nerves and blood vessels

Enamel and dentine are special substances made only for teeth. Both are much harder and tougher than ordinary bones. Tooth enamel is the hardest material in the whole body. Bone will grow and knit itself together when broken. But not so the teeth. When a tooth is injured, it can never repair itself. This is why a check up with the dentist every six months is so important. For when enamel or dentine decays, the body had no way of repairing the damage.